Boeing-machine



P. BOSCH.

BORING MACHINE.

APPLICATION FILED Ffa. l5. |919.

Patented Aug. 26, 1919.

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POMPEIN BGSCH, OF ELG-IN', ILLINOIS.

BORING-MACHINE.

Specicatlon of Letters Patent.

Patented Aug. 2c, 1919.

A Application tiled lFebruary 15, 1919. Serial No. 277,165.

-engine cylinders particularly the closely grouped cylinders of a gas engine casting.

rtmother object is the provision of improved means for centering the cutting tool within the cylinder to be bored.

Another object is the provision of improved means for steadying the cutting tool during the boring operation.

A further object is theprovision of a novel form of centering device applicable to one end of the cylinder to be bored and adapted to be moved from the cylinder by the tool, carrier as the latter is fed through the cylinder, whereby the centering device is prevented from obstructing the completion of the boring process.

A still further object is the provision of a novel form of framework adaptable to an engine without its removal from the vehicle in which it may be positioned, whereby the boring tool is accurately centered within the cylinder to be bored and is very rigidly supported therein.

Other objects and advantages of the invention will appear from the following descripticn taken in conjunction with the accompanying drawings which form a part of this specification and illustratethe preferred embodiment of the invention.

ln the drawings:

Figure 1 is a vertical longitudinal section through the plane defined by the axes of four automobile engine cylinders in a single casting, showing my invention in operative position therein and partially sectionedV in the said plane.

Fig. 2- isa section taken approximately on line 2--2 of Fig. 1.

, Fig. 3 is a section taken approximately on line 3--3 of Fig. 1.

Fig. 4 is a top plan view of a centering disk forming part of the present invention. Reference numeral 10 indicates generally a gas engine casting having the cylinders 11,

12, 13 and 111 and the water jacket 15. This casting l0 comprises the work to be operated on, ita-,ing assumed that the cylinder 13 of the casting is to be bored.

At 16 is indicated the main frame member of my invention comprising preferably a solid cylinder of iron having a diameter slightly less than that of the cylinder 12 in which it depends so that a slight space 17 is left between the wall of engine cylinder 12 and the wall of the main frame member 116. This main frame member is also somewhat shorter than the vertical length of the engine cylinder l2 so that its lower end does not reach quite to the bottom of the latter. A circumferential flange 18 is formed at the upper endl of main frame member 16 and rests upon the upper edge of the wall 1,9 of cylinder 12. An upper frame member `21 is fastened as by bolts 22 to the top of main frame member 16 and comprises an arm 23 positioned to extend over the cylinder 13 to be bored, arm 23 terminating above cylinder 13 in avertica'lly drilled and tapped boss 24, boss 24 being eccentric' with respect to the axis of cylinder 13.

The lower frame member of my invention is indicated at 25 and preferably comprises a short solid iron cylinder centrally bored for accommodation of a lag bolt 26 which has its upper end threaded into a center tapped aperture provided in the bottom of the main frame member 16. frame member carries an arm 27 spaced considerably below the casting 10 and carrying at its extremity a boss 28 positioned centrally below the axis of cylinder 13 and provided with a vertical bore 29 co-axial with ythat cylinder. A vertical shaft 31 is positioned at its lower'end in bore 29 where it is secured by a set screw 32, the shaft projecting upwardly through and co-axial with cylinder 13 to a point somewhat above the up er surface of casting `10.

pace 17 provides a limited range of horizontal movement in the main frame member 16 whereby the lower frame member may be set to the exact center to be maintained in boring cylinder 13.

A rotatable tool carrier 33 is mounted on shaft 31 and at its enlarged lower end carries the cutting tool 34 which is adapted to follow a helical path from one end to the other of cylinder 13 in boring out that cylinder.

Tool 34 is set at an angle to the tangent of cylinder 13 at the point of contact between the tool and the cylinder and is pref- The lower erably held in the carrier byy means of a set screw 35.

p vertical travel therein.

The power shaft 39 supports the tool carrier, rotates it and likewise feeds it longitudinally of shaft 31 during the cutting op eration.

Formed on supporting ring 38 and projecting toward cylinder 12 is a vertically bored bearing lug 41, the bore of this lug being co-axial with the bore of the boss 24 on the upper frame member. of this lug is smooth and it is engaged by the smooth lower end of the power shaft 39, the thread of the 4power shaft terminating at the upper end of lug 41. The lower endof the power shaft extends downwardly to the plane of the lower surface of the 'circular rack 36 and carries on its extremity and fixed thereto, a power pinion 42 meshed with the rack 36. This pinion lies flush against the lower end of the lug 41 and lthe weight of the tool carrier is -supported by the-pinion 42 through lug 41 and ring 38. The upper end of the power shaft is provided with an operating hand wheel 43, though, obviously, the shaft might be operated by connection with any convenient source of power other than the hand of the operator. -As the tool carrier rotates about shaft 31 it also turns within the supporting ring 38.

A lug 44, integral with lug 4l, projects therefrom at right angles and into its vertical bore is rigidly fixed a brace rod 45 which parallels the power shaft 39 and fits v snugly and slidably within a smooth vertical aperture provided in the lug 24 of the upper frame member.

Near its lower end the shaft 31 carriesv a frusto-conical centering disk v46 which is closely fitted on the shaft but not so snugly as to prevent its sliding along the shaft. By engagement between the conical surface 47 of the disk and the sharp annular lower -edge 48 of cylinder 13 the shaft 31 is instantly centered in the cylinder. Coiled about shaft 31 is a helical spring 49 which is interposed between lower frame boss 28 andthe centering disk ,to hold the disk up against the cylinder edge during ne assembly ofthe boring machine.

In assembling the boring machine on a cylinder casting (this invention being peculiarly adaptable to the boring of Ford engine cylinders) main frame member 16 is The bore 'tool carrier strikes the centering disk 46 hnug by its flange 1'8 within cylinder 12 and lower frame member 25 is loosely secured j to the main frame member by partially threading bolt 26 into the latter. Arm 27 is now swung to allow disk 46 to seat against 70 the lower edge 0f cylinder 13 whereby the shaft 31 is' centered in that cylinder. Upper arm 23 and upper frame member l21 are now lowered upon the main frame member, the tool carrier being simultaneously slipped upon shaft 3l, and bolts 22 a're set, the main frame, member, if necessary, being given such slight-axial rotation'as will bring bolts 22 into register with their tapped holes in thetop of themain frame member. Bolt 2G is now set tightly, completing the assembly.

In the operation of the machine, and con- Sidering the tool carrier as starting from the upper end of shaft 31, the rotation of power shaft 39 applies power to the tool carrier through, pinion 42 and rack 36 to rotate the carrier, the lgradual lowering of the power shaft through boss 24 feeding the tool downwardly as it turns. When the the spring 49 yields and permits a suficient de'pression of the disk as will allow the tool 34 to cut to the bottom of cylinder 13. Obviously .any of the several cylinders of a casting may be similarly bored by setting the main frame member in the adjacent cylinder. For the purpose of assembling, the supporting ring 38 is madein two'parts as shown in Fig. 3. By means 100 of a plurality of holes 51 the chips cut by tool 34 may be allowed to drop from the cylinder 13 in order that there shall not be a body of chips of uneven depth upon the disk to interfere with the depression of 105 the disk ywhen the tool carrier approaches the lower end of the cylinder. 1

The function of the brace rod is to steady the tool carrier and tool against chattering, to lend support to the shaft 31 in a direc- 110 tion longitudinally of the cylinder casting,

-and to brace power shaft 39 in a direction transverse to the length of the cylinder castlng, thus overcoming the tendency of the tool carrier and rack 36 to bend the power 115 shaftl while the tool is cutting. Should it be necessary to replace tool 34 during thel lcutting operation, because ofbreakage, for

precise embodiment shown, except in so far as the same is limited in the appended claims.

The upper surface 52 of the lower frame member 25 definesaA plane standing exactly at right angles to the axis of the shaft 81. This surface 52 is placed in flat contact with the fiat bottom surface of the cylinder casting l0 in centering the shaft 31 in cylinder 13'. With these .two surfaces in flat contact the shaft 31 is centered in cylinder 13 when the edge 48 of the cylinder is in contactall-around with thel coni- .cal surface 47` of disk 46.

15 I claim:

l. In a machine for` 'boring cylinder castings, the combination with a tool carrier shaft adapted to be positioned centrally within the cylinder to be bored, of devices for centering said shaft, comprising a lower frame member in which the shaft is rigidly carried, said frame member having an upper surface definirg a plane at right angles tc t ie axis of the shaft, and a disk mounted on tne shaft and having a conical surface of sufficient diameter to contact with the lower edge of the cylinder to be bored.l

2. In a machine for boring cylinder castings, the combination of a lower frame member attachable to said casting and having a plane upper surface, a tool carrying .shaft rigidly mounted on said frame mem- Iber with its axis at right angles to said plane surface, the connection between the frame 35 member and the shaft being positioned below said plane surface, a centering disk concentrically mounted on the shaft and having an up-turned conical surface, and a spring `interposed 'between said disk and l 4.0 the frame member. f

8. Ina cylinder boring machine the combination with a tool carrier shaft extending rigidly and co-axially with a cylinder to 'be bored, of a tool carrier slidably and rotatably mounted on said shaft, an annular rack formed on said carrier, there being an annular channel formed in the' carrier in a plane parallel with thatof the rack and at right angles to the axis of the carrier shaft, a rigid frame having a tapped boss eccentrically positioned and spaced opposite an end of the cylinder to be bored, a power shaft threaded into said boss, adapted to travel therein, and overlapping the tool carrier, a pinion meshedl with said rack and fixed upon the end of power shaft, a supporting ring rotatably fitting the channel of the tool carrier, and a lug fixed upon said ring, bearing against one end of said pinion,

6o and rotatably fitted by a smooth portion of said power shaft.

t In a boring machine, the combination with a rigid tool carrier shaft, of a tool carrier rotatably and slidably mounted thereon, a circular rack formed 4on said pinion.

5.v In a cylinder boring machine, the com- 30 bination with a tool carrier shaft extending fixedly and co-axially through a cylinder to be bored, of a tool carrier rotatably and slidably mounted on said shaft, a tapped boss rigidly positioned opposite an end of the cylinder to be bored and eccentric with respect to said shaft, a power shaft threaded into the boss for travel therethrough in a direction paralleling the tool carrier shaft, connections whereby at rotation of the power shaft revolves the tool carrier, an apparatus engaging the tool carrier and power 'shaft whereby the axial travel of the power shaft feeds the tool carrier longitudinally of its shaft. 95

6. In a cylinder boring machine, the combination with a tool carrier shaft concentrically fixed within the cylinder to be bored,

of a tool carrier rotatably and slidably mounted thereon, a straight-tooth gear provided on the tool carrier, a supporting ring rotatably seated in a peripheral channel pro- Vvided in the tool carrier, a rigid arm projecting radially from said ring and having an aperture paralleling the tool carrier shaft, a stud rigidly projecting at ri ht angles from said'arm, a fixed frame mem er comprising a boss positioned opposite an end of the cylinder to be bored, and having a tapped aperture4 axially alined with the 110 aperture of said rigid arm, there being also formedl in said boss a smooth aperture having its axis parallel to the axis of saidl tapped aperture, a power shaft in threaded engagement with the tapped aperture of the boss for axial travel therein, said power shaft having a smooth portion rotatably fit ting the aperture of said rigid arm, a straight-tooth pinion fixed upon the power shaft and meshing with the circular rack of the tool carrier, and a brace-rod slidably engaging the smooth aperture of said boss and havmg an end rigidly connected to said stud.

7 In a cylinder boring machine, the com- 125 bination with a tool carrier shaft, of a frame comprising a fixed boss having spaced parallel apertures one smooth and onel tapped said apertures having their axes paralleling the shaft of thetool carrying shaft and eccentric thereto, the tool carrier slidably and rotatably mounted on the tool carrier shaft, a power shaft threaded for travel in the tapped aperture of the boss, connections between the power shaft and the tool carrier whereby the former rotates the latter7 a supporting ring having rotatable engagement with the tool carrier, a brace-rod slidably tting the smooth aperture of said boss, said brace-rod being rigidly connected to said supporting ring, and said' power shaft being rotatable only with respect to said supporting ring and in pivotal connection therewith.

8. In a boring machine, the combinatie .cylinder upon the shaft.

with a frame member comprising an arm positioned opposite and spaced from an end of a cylinder to be bored,"of a tool carrier shaft rigidly mounted on said arm and eX- tending co-aXially through said cylinder, a'

centering disk slidably mounted on said shaft, a spring interposed between the arm and disk to seat the disk yieldingly against the end of the cylinder, anda tool carrier rotatably and slidably mounted within said .In testimony whereof I have aiiixed my signature.

PoMrEiN BoscH. 

